This brings back memories before it was archived in the sidetracked series. The cache was Thomas the tank engine. Unfortunately the Dartmoor Railway is no longer functioning but updates can be got on here https://www.dartmoor-railway-sa.org/

The headline co ordinates bring you to two notices from which you need to take information from to find the cache.

NB The information you need is NOT from the Dartmoor Railway notice.
 

Sum of second word on first row = A

Sum of last word on fifth  row  = B

Sum of last word on second row  =C

CHECKSUM OF ABC = 16

The cache can be found at N 50° 46.A B B

W 3° 56. B C ( C-2)